遼西早白堊世似尾羽龍新材料的研究.pdf

1、編號：碩士學位論文碩士學位論文題目：遼西早白堊世似尾羽龍新材料的研究培養(yǎng)單位：古生物學院專業(yè)名稱：動物學指導教師：周長付教授研究生：劉東旭完成時間：2014年5月20日沈陽師范大學研究生處制類別全日制研究生√教育碩士同等學力IINewMaterialofSimilicaudipteryxfromtheLowerCretaceousofWesternLiaoningAbstractTheJeholBiotaisasignificantte

2、rrestrialbiotaoftheCretaceousontheEarth.Itisfamouswithexquisitefossilsoffeathereddinosaurs,earlybirds,earlymammals,andearlyfloweringplants.Ofthese,discoveriesofthefeathereddinosaursprovidefossilevidencesinunderstandingma

3、jorevolutionaryeventsinoriginsofthebirds,feathersandbirdflighting.Amongthesefeathereddinosaurgroups,Caudipteryxisfamousthatarousedmajorargumentsinitsrelationshipwithdinosaursorbirds.Withmorefossildiscoveriesandfurtherstu

4、dies,asabasalgroupofoviraptorosaurians,CaudipteryxhasacloserelationshipwithSimilicaudipteryxandIncisivosaurus,butthelattertwomoreprimitive.Unfortunately,theonlyknownfossilofIncisivosaurusisanisolatedskullandjaws;whereaso

5、urknowledgeofSimilicaudipteryxismainlylimitedinpostcranialmorphology.Therefore,bothtwotaxaneedbefurtherconfirmedintaxonomyandrelationship,aswellastheirrelationshipswithCaudipteryx.Inpresentstudy,anearlycompleteskeletonof

6、SimilicaudipteryxisfromtheEarlyCretaceousJiufotangFormationofChaoyang,westernLiaoning.Itpossiblyrepresentsanadultindividualwiththelargestsizeasknown.ThespecimenshowsthecharacteristicofSimilicaudipteryx,suchas,antorbitalp

7、ortionshorterthan50%oftheskull,externalnarishighlypositioned,teethpresent,dentarysymphysis“U”-shaped,metatarsalIIIbilaterallycompressed,cuppedicusfossaweaklydeveloped,tailshortwithsword-liketerminal,manualdigit3unreduced

8、,hypophysisofdorsalvertebrapresent.Inaddition,thespecimenprovidesmorevaluableinformationofSimilcaudipteryx,suchas,firstpremaxillarytoothwelldeveloped,maxillarytoothpresent,maxillaryprocessofthejugalband-likeandconstricte

9、dbasally,posteriorprocessofthequadratojugalwelldeveloped,dorsalvertebraelessthannine,scapularacromionwelldeveloped,obturatorprocesswelldeveloped.Moreover,SimilicaudipteryxshowsasimilaritywithIncisivosaurusinsomecranialfe

10、atures,suchasnutrientforamenabsentalongthebuccalmargin,premaxillarytoothincise-like,maxillarytoothpresent;anddifferentfromthelatterinhavingexternalnariselongated,obitalrimofthejugaltightlycurved,squamosalprocessofthequad

11、ratojugalnearlyvertical,fivepremaxillaryteeth,posteriorpremaxillaryteethdistallycurved.ThesedifferencesfurthersupportthetaxonomicvalidityofSimilicaudipteryxandIncisivosaurus.Inaddition,apossiblemosaicevolutionisdiscussed